bowing hardiplank

[arlene matzkin]

I am the architect for an almost finished new house sided with Hardiplank clapboards. The first plank under each window is bowed out. All of the planks are blind nailed.

Is there a way to remedy this other than putting in nails at the bottom of the bowed pieces? Is there an adhesive application. Has this happened to anyone else?

[Jim Katen]

Since it's blind nailed, there are no nails at the first course below each window and the planks are just doing what they do.

Carefully drill and countersink holes in the bowed areas and gently screw the planks down with regular old deck screws. Patch over the screw heads with bondo if you like. I did this with my house 23 years ago and the Hardi is still doing fine in those areas.

Lately, I've seen some builders address this problem with a pin gun. It seems to work fine as well and is a heck of a lot quicker.

[jjeffzehnder]

This seems to be more of an issue when the plank is one piece across the entire window than when there is a joint somewhere under the middle of the window.

[kurt]

I've done the same thing as Jim with finish screws. Not supposed to, but it works.

[Chad Fabry]

I pre-drill and use 6 penny trim head stainless ring shank nails just under the sill.

[mlparham]

This seems to be more of an issue when the plank is one piece across the entire window than when there is a joint somewhere under the middle of the window.

I would agree with Jim that this repair will work. However, I recommend that you consult with the manufacturer before you proceed. Blind nailing combined with face nailing may void the warranty on the siding. The installation directions are very clear that both are not allowed.

[mark parlee]

Face nail it under the windows. The only way the warranty is voided is if you go against warrantable application instructions, and that particular piece fails, than that particular piece will not be warranted.

[Rob Amaral]

Did you leave a gap below the sill over the board??